Fluid lift for use in wells



Feb. 9, 1932. J. PENROD FLUID LIFT Fo USE IN wELLs Filed April 26, 1929 4 Sheets-Sheet 1 Sinw v Feb. 9, 1932. J. PENROD FLUID LIFT Foa UsE 1N wELLs 4 Sheets-sheet 2 Filed April 26. 1929 el Pen rod Clttoxneq 4 Sheets-Sheet 'I5 J. PENRCD FLUID LIFT FOR USE IN WELLS Filed April 26, 1929 Feb. 9, 1932.

Feb. 9, 1932.

J, PENRODV FLUID LIFT FOR USE IN WELLS Filed April 26. 1929 4 Sheets-Sheet 4 gwuzntot 43 Pfwao Patented Feb. 9, 1932 UNITE JOHN PENROD, OF OKMULGEE, OKLAHOMA, ASSIGNOR OF ONE-HALF T ROBERT D.

THOMPSON, OF' OKMULGEE, OKLAHOMA FLUID Lrrr ron Usn In wnLLs Application filed April 26,

l aids to the recovery of the fluid to the end that the natural force such as the gas pressure under the influence of which the oil or the like enters the well is conserved and the external power required to operate the pump i... reduced as compared with other iiuid lifts of -lll the same capacity, the arrangement being such, however, that the natural gas pressure employed as ,an aid in the I'recoveryof lthe liquid is prevented from interfering with the operation of the pump.

A further aim is to provide a fluid lift in which -the increased tubing pressure prevailing during the up stroke of the pump is relied on to build up pressure in a number of separate chambers for action in concert with forces such as the weight of the reciprocating parts in accomplishing the down stroke of the pump against the column of casing fluid thru which pressure was transmitted from the surface to a'ect the up stroke of the pump, it being apparent that the forces combined to bring about the down stroke are .of` an order of mzgnitu'de superior' to that of the force of the column of casing liquid when the pressure on the latter is relieved.

Another feature of the invention will he found to reside in the means by which the presence of sand in the iuid being elevated is preggented from causing rapid `wear of the working parts of the pump and in the means by which the cups and other sealing devices of the reciprocating portion of the pump are relieved of .destructive Huid pressure.

A further object is to provide a luid lift in which the packer relied on to-establish a sealbetween the pump and the casing may be relieved of the weight of the pressure medium in the casing to allow` of the ready withdrawal of the pump to the surface.

Other objects and advantages will be yap- 1929. Serial No. 358,376.

parent during the course of the following description.

ln the accompanying drawings forming a part of this application and in which like numerals are employed to designate like parts throughout the same,

Figure l is a vertical sectional view through the upper portion of the improved pump, the parts b-eing in the positions occupied on theup stroke.

Figure la is a similar view through the i11- termediate portion of the pump.

Figure 1b is a similar view through the lower portion of the pump.

Figure 2 is a vertical sectional view through the upper portion of the pump, lthe parts being shown in the positions occupied on the down stroke.

Figure 2a is a similar view .through the intermediate portion of the pump.

Figure 2b is a similar view through the lower portion of the pump.

Figure 3 is a vertical sectional View through the upper portion of a modified form of pump. n y

Figure 3a is a similar View through the intermediate portion of the modif-"led form of pump.

Figure 3b is a vertical sectional view through the lower portion of the improved pump.

Figure 4 is a vertical sectional view through the improved fluid lift, parts being broken away. r

Figure 5 is a vertical sectional view through the upper portion of the pump shown in Figures l, la and 2a, the movable piston and other part-s being shown in elevation.

ln the drawings, the numeral l() designates a perforated nipple by which the native.

well fluid is allowed to enter the pump for passage. upwardly thru a standing valve 11 and into a low pressure pumping chamber 1, formed withinxaJ working barrel 12. A bushing l-l provides a-means by which the perfoi-ated inlet nipple l() and the standing valve 1l are suspended from the working barrel. 1

A plunger 16 is mounted for reciprocation within the working barrel l2 and'is provided at the lower portion thereof with a traveling valve 18 by which the discharge of fluid from the original pumping chamber 1 is controlled. l A series of cups or other sealing devices 2O are mounted on the plunger 16 andare protected in a manner to be fully hereinafter described.

As shown in Figures 2a. and 2b, a `fluid conduit 22 has rigid connection with the plunger 16 and receives the native well fluid discharged from the same and conducts such fluid upward into a second pumping chamber 2 of substantially greater volume than that of the original pumping chamber 1. More specifically, the conduit 22 has connection with a bushing or spider 24'to which an inlet valve 26 to the chamber 2 is attached.

The pumping chamber 2 is shown in Figure 2a to be formed within a vertically movable sleevelike piston 28 attached rigidly to the spider 24 to move with the fluid conduit so that on the up stroke, the volume of the chamber 2 is diminished and the fluid previously admitted to this chamber is discharged out through the upper portion thereof by way of a standingvalve 30. The standing valve 30 is suspended from a fixed depending working barrel 32 within which a pumping chamber 3 is formed for the reception of the fluid discharged from the chamber 2.

During the enlargement of the pumping chamber 2, such gas as may be therein is allowed to expand and consequently Athe ready admission of the liquid from the conduit 22 into the chamber 2' is allowed. Thus, both the chambers 1 and 2 might be said to be low pressure pumping chambers and, asfis believed to be clear, the chamber 1 operates only against the pressure of the fluid between the chambers 1 and 2, While the chamber 2 operates only against the pressure of the fluid in the chamber'3.

The fixed depending working barrel 32 receives a plunger 34 which is moved upward concurrently with a similar movement of theA piston 28 to enlarge the chamber 3 simultaneously with the decrease in the volume of the chamber 2. The plunger 34 is provided with a traveling valve 36 which, as is believed to be apparent, is moved to open position on the down stroke and to closed position on the up stroke. The plunger 34 is suspended from and is movable with what might be said to be the upper section 38 of the fluid conduit 22, and fluid discharged from the chamber 3 is passedupward through the descending section 38 and into the annular bypass pumping chamber 4.l

The by-pass chamber 4 is formed between a vertically movable piston 40 and a plunger 41, both the members 40 and 41 having rigid connection with a second spider 42 mounted upon the upper terminal of the section 38.

The spiders 24 and 42 are joined rigidly by a tie member in the nature of a tube 43 so that thepa-rts connected to the spiders are caused to move in unison. More specifically, the connection between the spiders 24 and 42 .causes the plungers 16, 34 and 41 and the pistons 28 and 40 to move together to bring about the relaying of the fluid through the various chambers.

As shown in Figure 2, the plunger 41 is attached to the spider 42 by an inlet valve 44, movable to unseated position on the down stroke to allow of the admission of fluid to the chamber 4 and adapted to seat or close on the up stroke during which fluid is discharged from the chamber 4. The cage of the valve 44 is shown to be slotted for the discharge of fluid up through the bore of the plunger 41 and through the outlet valve 46. Figure 2 also illustrates .that the plunger 41 has a Working fit within a fixed depending barrel 48, the upper portion of which is open for the discharge of fluid into the tubing 50 by Way of a standing Valve 52.

The )revision of the standing valve 52 allows o the free ascent of the fluid in the tubing under the influence of the ascending plunger 41 and inhibits retrograde movement of such fluid during the descent of the plunger. Any desired number of standing valves may be placed in the tubing to distribute the pressure of the tubing fluid, it being ynoted in this connection that excessive pressure on ball valves isconducive to rapid wear and the points in the tubing prolongs greatly the period possible to operate the pump without interruption for repair.

The standing valve 52 is shown in Figure 2 to be suspended from a nipple 54 of a suitable length and arranged within a housing 56 to cooperate therewith in the formation of an annular gas trap 58, the members 54 and 56 being held in spaced relation by a bushing 60 through the medium of which these parts are attached to the tubing and by which the upper end "of the trap 58 is closed.

In carrying out the invention, the annular trap 58 is placed in constant communication with the outlet portion of the barrel 48 and toy receive a portion of the gas content of the fluid being elevated so that as a result of a short period of. operation,J the pressure within the chamber 58 will be built up to an order of magnitude sufficient to offer substantial aid to the down stroke of the pump as will be described. A

The lower portion` of the housing 56 is connected by a bushing 62 with a cylinder 64 arranged outwardly of and cooperating with the fixed depending barrel 48 in the formation of an annular chamber 66 containing an initially compressed isolated body of gas. Suitable means such as a Valve 68 may be employed to furnish gas under pressure to the chamber 66. Of course, the gas under pressure 1s furnished to the chamber V66 pre-- paratory to the installation of the pump into the vertically-movable piston 40 is flanged inwardly and is held in sealing engagement with a shoulder on the intermediate portion of the barrel 48 so that during the descent of the pump into the well, the lower portion of the chamber 66 will be closed effectively and the loss of pressure prevented.

In addition to thetemporary seal defined by the shoulder 70 and the inwardly flanged upper portion of the piston 40, the piston is provided with a plurality of sealing rings or cups 72 having a fluid tight contact with the cylinder 64. rlhe sealing devices 72 not only prevent compressed gas within the chamber 66 from passing between the piston and the surrounding cylinder 64 but inhibitt-heincursion of casing liquid inte the chamber. However, the small quantity of casing liquid that may as a result of wear be allowed to Work by the rings 72 is discharged by gravity into the chamber 4. Such discharge of liquid from the chamber 66 takes place between the enlarged intermediate portion of the depending barrel 48 and the adjacent portion of the cylinder 64.

As shown in Figures 2 and 2a, the lower portion of the fixed cylinder 64 has rigid connection with the upper portion of the depending barrel 32 and a second cylinder 76 is attached rigidly to the intermediate portion of the barrel 32 as indicated at 78. It will be seen that the cylinder 76 surrounds and is spaced outwardly from a portion of the depending barrel 32 to cooperate therewith in the formation of an annular chamber 80 containing an initially compressed isolated body of gas, the same being introduced into the chamber 80'by way of a valve 82. As in the case of the chamber 66, the chamber 80 is supplied with gas under pressure preparatory to the installationof the pump into the well.

The piston 28 is movable into the chamber 80 from the lower end thereof and has a iiuid tight Contact with both the barrel 32 and the cylinder 76 by sealing devices 84 and so that the incursion of casing liquid into the chamber and the loss of pressure from the chamber is prevented.

The lower portion ofthe fixed depending working barrel 32 is enlarged to form a shoulder for contact with the inwardly ilanged upper portion of the piston 28, so that the descent of the piston is limited lf desired, a stratum of oil may be carried in the chamber 8O to furnish lubrication and at the same time aid in sealing the chamber. Figure 2a illustrates that the depending cage of the standing valve 30 is spaced in from the wall of the piston 28 to cooperate therewith in the formation of a gas trap between the pumping chamber 2 and the pressure chamber 80 so that the ascent of sand into the chamber 8O is prevented and the sealing devices 84 protected from destructive contact by the sand.

Coming now to the means by which the fluid conduit 22 and the parts such as the plunger 16, 34 and 41 and the pistons 28 and 40 are moved on the upstroke, it is pointed out that the casingl is adaptable for the reception of a fluid such as oil, water or air by which a pressure created on the surface may be transmitted down through the well to the pistons 28 and 40 to raise the same.

Figures 2 and 2a illustrate that the lower portions of the cylinders 64 and 76 are provided with openings or slots 92 and 94 respectively, by which fluid under pressure may enter the cylinders and displace the pistons 28 and 40 to bring about the up stroke of the movable parts of the pump. rl`he application of pressure to the pistons 28 and 40 and to the spiders 24 and' 42, respectively, will bring about the ascent of these .parts and since, as previously stated, the spiders are joined by a tie member 43, these parts will be moved in unison.

The source of power on the surface for plac ing the casing liquid under pressure acts at regular intervals to bring about the upstroke and, of course, each pressure period is timed to bring about the desired length of stroke and during each up stroke the pressure prevailing within the chambers 58, 66 and 80 is built up to a point sufficient to cooperate actively with the weight of the movable parts of the pump in bringing about the down stroke.

As shown in Figure 1b, the pump is provided slightly beneath the several pressure4 iuid motors with a packer excluding the pressure medium in the casing from the space below. rlhe packer embodies inner and outer spaced tubular sections 97 and 98, respectively, the inner section being provided with a plurality of "sealing devices such as cups 100 having fluid tight Contact with the intermediate portion of the outer section 98.

The outer section 98 of the packer is pro= vided with a second series of packing devices such as rings 102 for fluid tight 4Contact with the casing 90. lt is believed to be clear that since the upper end of the section 98 is entirely lopen, the pressure fluid in the casing may act agamst the upper surfaces of the sealing devices 100 and 102 to provide a ositive` anchor means by which vibration incident to forced reci rocation of the movable parts of the pump is combatcd edectively.

' The cups 100 are seated between the upper and lower rows of fluid discharge passages reA 104 and 106 in the outer section 98 and when passes down through the ports 104 and out throughl the ports 106 to a point below the outer cups 102 to the end that the pump may be withdrawn without the necessity of, at the same time, swabbing the liquid out of the casing. Otherwise expressed, the provision of the packer shown in Figure 2a allows the casing. liquid to be dumped down into the lower portion of the well preparatory to the withdrawal of the pump.

It will be seen that the outer section 98 is provided with an internal shoulder 107 in the path of travel-of and adapted for engagement by an annular shoulder 108 on the tubular member 110 so that the movement of the inner section 97 with relation to the outer section 98 is limited. By this arrangement, after a predetermined upward movement of the inner cups 100, the outer section 98 and the cups 102 carried thereby are picked up and withdrawn along with the rest of the equipment.

Referring now to Figure 2?), it will be seen that the outer section 98 of the packer has rigid connection at the lower portion thereof with a housing 112 through the medium of a bushing 114. The housing 112 surrounds the fluid conduit 22 and the Working barrel 12 and is spaced therefrom to forman annular chamber in which a body of relatively clean fluid .is carried. y

Itis the function of the fluid in the housing 112 to aid the cups 20 in resisting the pressure within the chamber 1 during the descent of the plunger 16 and the forced discharge of well liquid into the conduit 22. On' the down stroke of the plunger 16 against the pressure of the liquid in the pumping chamber 1, the liquid in the housing 112 has the ei'ect of equalizing such pressure to protect the cups 20. Thus, on the down stroke the substantially equal pressures on opposite ends of the cups 20 act with the sealing efl'ect of such cups in preventing the well fluid in the chamber 1 from passing about the exterior of the cups and possibly depositing sand between the conduit 22 and the surrounding portion of the barrel 12.

Preparatoryvto the installation of the im'- proved pump into the well, the housing 112 is supplied with a suitable liquid and the pumping chambers 1, 2, 8 and 4, and the conduits 22 and 38, are also furnished with liquid. Suflicient fluid is introduced into the housing 56 to fill the upper portion of the barrel 48 and close the inlet end of the standing valve 52 to seal the gas trap 58. After the pump has been run into the well on the tubing and seated, the tubing is filled with fluid froln an outside source. In further preparing for operation, a liquid from an outside source is i11- troduced into the casing to act as a pressure transmitting medium by which pressure created on the surface may be applied to the pump to bring about the up stroke thereof.

lVhen the pump is started, the unseating of the inwardly flanged upper end of the piston 40 will result in the movement of a portion of the compressed air or gas in the chamber 66 down between the opposed surfaces of the members 40 and 48 through the pumping chamber 4 and up through the members 41 and 46 for entrance into the trap or pressure chamber 58. Of course, the compressed air or gas released from the chamber 66 is excluded from the tubing by the liquid already therein and consequently an approximate equalization of the pressures within the chambers 66 and 58 will be established.

During the initial period of operation, the pressure prevailing within the chambers 58, 66 and will, when combined with the weight of the reciprocating equipment, be suiiicient to at least impart a limited down stroke to the reciprocating equipment against the temporarily reduced pressure prevailing within the casing. However, as a result of a short period of operation, the ascent of native well fluid through the barrel 48 and the housing 56 will result in the accumulation of sufficient gas pressure within the trap 58 to co-act effectively with the other agencies herein described in bringing about full length down strokes.

It will be seen with reference to Figures 1 and 1a that the pistons 28 and 40 are of a cross sectional area less than that of the chambers into which the same ascend so that a substantial minimum pressure may be provided in these chambers without a substantial increase in pressure during the ascent of the pistons.

The inner section 110 of the packer is seated on the bushing 114 and is provided with a plurality of -inverted cups 116 having `fluid tight contact with the outer section 98 and constituting a means by which the native well liquid in the casing below the cups 102 is held separate from the column of .liquid in the housing 112. Furthermore, should the close working fit between the inner packer section 97 and the conduit 22ybecome worn and the passage of pressure casing liquid between these parts allowed, such liquid is prevented from finding its way into the space beneath the packer by way of the openings 106. By this arrangement, the cups 116 first separate the native well fluid in the casing below the pacliervfrom the fluid in thehousing 112, and, second, prevent the pressure fluid above the packer from passing between the members 97 and 22 and mingling withethe native well fluid present in the lower portions of the casing.

On the up stroke of the pump, the chamber 1 will be filled with fluid from the well and on the subsequent down stroke, the ball valve 1-8 will be unseated and the fluid originally admitted to the pumping chamber 1 is directed up through the plunger 16 and the conduit 22 for movement into the substantially larger pumping chamber 2.

On the up stroke, the inlet valve 26 to the chamber 2 is seated while the ascending piston 28 will reduce the volume of the chamber and direct the fiuid therein up through the standing valve 30 into the concurrently enlarging chamber 3. Of course, during the up stroke of the plunger 34, the traveling valve 36 is seated and on the down stroke, the fluid previously admitted to the chamber 3 is discharged byjvay of thefplunger 34 and the conduit section 38 into the concurrently enlarging annular hyd-pass chamber 4.

With particular reference to Figure 2, it will be seen that on the down or inlet stroke of the piston 40 the` inlet traveling valve 44 is unseated to admit fluid under pressure to the chamber 4, during which stroke the upper outlet traveling valve 46 remains seated 'under the pressure above. Now, on the subsequent up stroke of the piston 40, the volume of the chamber 4 will be'diminished and the iuid therein will be directed up through the slots in the cage of the valve 44 and through the plunger 41 so that the ball 46 is unseated against the pressure above and the fluid discharged into the high pressure chamber between the valve 46 and the bushing 60. 0f course, when the pressure incident to the ascent of the plunger 41 exceeds that of the tubing pressure, the ball 52 unseated and the fluid directed up into the tubing.

It will be seen that the operation of the pump may be caused to build up any desired pressure within the chamber 58 by an appropriate restriction `of the fluid passage through the standing valve 52 to an area less th an the cross sectional area of the barrel 48, as illustrated, or by otherwise throttling the ow of the native well fluid through the tubing. Pressure may be built up in the chamber 58 to a value substantially superior to that prevailing within the tubing so that y on the down stroke of the pump the pressure the intervention of the somewhat higher presn@ therewith in the formation of .gastrap by which the ascent of sand into destructive contact with the close workingwithin the trap 58 may be relied on to furnish substantial aid in moving the reciprocating equipment.

Attention is now invited to ,Figure 2 in which it is illustrated that the discharge of fluid from the chamber 4 is accomplished by the ascent of the spider 42 andthe piston 40 to reduce the volume of the chamber 4 from the lower end thereof whereby the fluid is directed up through the plunger 41 and into the outlet portion of the barrel 48. rll"his necessitates the discharge of liquid into the already ascending Huid in thel barrel 48 or the tubing, giving the moving fluid a rate of ascent twice that of the rate of descent.

The lower portion of the barrel 48 is spaced inward from the (piston 40 to cooperate an annular operates within the dependin surfaces of the piston 40, the barrel 48 and the plunger 41 is prevented. l

In Figure 2a, another arrangement of the inverted ypumping chamber is illustrated, wherein it is shown that the standing valve 30 is at the upper or outlet .portion of the pumping chamber 2, while the temporary closed lower portion of the chamber is movable upwardly in the direction 'of the standing valve 30 so that during such movement the fluid in the chamber will be discharged into thechamber 3 immediately above. lt. will be seen that the sealing devices 84 are located above ythe standing valve 30 and are protected from destructive contact with the sand laden fluid by the provision of the annular gas trap between the standing valve and the adjacent portion of the movable piston 28.

Also, -it is pointed out that the ow of fluid being recovered is confined to the central passages through the pump and is spaced from the close working surfaces thereof so that any sand that may be present in the Aliuid is prevented from having destructive contact with the close working surfaces.

Figure 2 illustrates that the upper portion of the cage of the traveling valve 46 is open to form what might be said to be a pocket for the collection of sand so that when the pump is not in operation any sand that might settle from the tubing iiuid is received within the cage and is Hushed out when pumping is resumed. rlhe upper portion ot the cage of the valve 46 is shown to be beveled outwardly to an edge for scraping engagement withthe wall of the surrounding barrel 48 so'that sand is prevented from lodging between the plunger 41 and the barrel..

' In broadly reviewing the invention, it will be seen that the two relatively low pressure chambers 1 and 2 are protected from the pressure of the entire column of tubing Huid by sure chambers 3 and 4, it being noted that the/ opening of the valve 46 on the up stroke will cause the pressure within the chamber 4 toF approximate the maximum pressure within the tubing, while the pressure within the chamber 3 will be found to be somewhat less than the maximum pressure within the chamber 4..

In the form of invention illustrated in Figures 3, 3a and 3b, the movable plunger 141 barrel 148 and has the upper portion thereo provided with a valve 146 having a cycle of operation the same as that of the valve 46.

As shown in Figure 3, the valve 146 discharges into an outlet chamber 147 formed within a sleevelike piston 150. The. upper portion of the piston 150 is slidably received within the annular gas trap or pressure chamber 152 formed by concentrically arranged 139 spaced inner and outer tubular members 153 and 154, respectively, the upper portions of which are joined by a bushing 156.

In carrying out this `formof invention, a limited clearance is provided between the opposed surfaces of the piston 150 and the depending tubular member 153 to allow a portion of the gas content of the native well fluid to be received and trapped within the chamber 152.

During operation, a portion of the gas in the native -well fluid will be trapped within .the chamber 152 and at the completion of each up stroke will act against the upper end of the piston 150 to co-act with the weight of the tubing fluid acting against the closed valve 146 andthe exposed portion of the bushing 160 to urge the reciprocating equip-I side of the bushing 160 sufficiently to allowl the' combined forces of the fiuids within .theV

tubing and the chamber 152 to overpower the casing liquid and elevate the same suiiiciently to accomplish the desired down stroke.

The employment of the weight of the tubing fluid as an aid to the down stroke is made possible by the fact that the fluid being elevated simultaneously from belowis beingreceived within the concurrently enlarging annular by-pass chamber 4 and is temporarily held separate from the tubing fluid.

The lower portion of the dependin member 153 is shown to be spaced inward y from the movable pistou 150 to cooperate therewith in the formation of an annular gas trap between the chamber 147 and the close working surfaces of the piston 150. More specifically, the provision of the annular gas trap about the lower portion of the member 153 prevents the native welluid passing through the chamber 147 from depositing sand on the close working surfaces of the piston and the rings 166 thereof. this arrangement, only the valve 146 is subject to the pressure of the fluid and the sand in such fluid.

Figure 3 illustratesthat a second gas receiving and trapping chamber 170 is arranged to receive a portion of the gas present in the fluid being recovered so that such gas may, upon completion of the up stroke, act expansively to aid the gas in the chamber 152 and the other agencies, such as the weight of the moving fluid conduit, in bringing about the down stroke at the desired rate of speed,

portion thereof to discharge the fluid be ing elevated into the tubing for ascent -to the surface.

During the initial period of operation and before suiiicient gas pressure has been built up in the chambers 152 and l17.0 to be effective aids to the down stroke, the'tubing fluid may be placed under pressure at the surface to positively bring about the descent of the reciprocating-pumping element. Now, after sutlicient gas pressure has been accumulated in the chambers 152 and 17() to cooperate with the weight of the Huid conduit and the pressure within thel chambers 66 and 80 to eliect full length down strokes, a one-way drop valve may be introduced through the tubing and seated within the member 175. The introduction of the drop valveinto the tubing will avoid a retrograde movement of thetubing Huid so that the pressure required to bring about the up stroke is minimized.

` The invention may be carried out by placing the various pumping chambers at the most suitable levels in the well. For example, the orignal low pressure pumping chamber 1 may be near the bottom of the well, and since the fluid conduit 14 may be of any length, possibly a thousand feet, the chamber 2 will be a substantial distance above the chamber 1, so that the chamber 1 will be subject only to the pressure prevailing within the conduit 14.

Of course, the chamber 3 will be positioned immediately above the chamber 2, while the annular by-pass chamber 4 may be 40 or more feet above the chamber 3 and will, on the up stroke, b e subjected to the maximum pressure prevailing within the tubing, such pressure being substantially less than the pressure Within a single pumping chamber fluid lift located at the bottom of a depth.

Having thus described the invention, what is claimed is:

1. Ina fluid lift for use in wells, upper and lower barrels having pumping chambers associated therewith, a movable pumping element having a conduit for the flow of iuid from one chamber .tothe other and being provided with -inlet and outlet valves for the chamber of the upper barrel, avtubingreceiv- Aillgllld from the upper barrel, and a body well of the same of compressed gas acting on and closing said outlet valve on the down stroke and urging the pumping element downward.

2. In a fluid lift for use in wells, upper and lower barrels having pumping chambers associated therewith, a movable pumping element having a conduit for the flow of fluid from one chamber to the other and being provided with inlet and out-let valves for the chamber of the upper barrel, a tubing receiving fluid from the upper barrel, there being means acting through the fluid elevated by said ypumping element to intermittently close said outlet valve and urge the pumping element downward, and a piston movable with the pumping element to reduce the volume of the chamber of the upper barrel on the up stroke of the pumping element.

3. ln a fluid lift for use in wells, a cylinder having a chamber adapted for the reception of a. compressible fluid and having a cl'osed upper portion, a piston movable into the chamber from the lower portion thereof, and a pumping element movable with said piston and. having a second chamber receiving said piston andadaptable for the reception of a pressure medium.

4. l'nra fluid lift for use in wells, a fixed member having a pumping chamber associated therewith,y a reciprocating pumping element having a piston for said chamber,

said reciprocating pumping element being provided with an inlet valve to said chamber and with an outlet valve traveling therewith and movable to open position on the up stroke of the pumping element, there being a second pumping chamber associated with said pumping element, said pumping element having means establishing communication between the first named chamber and said outlet valve and between the first and 'second named chambers.

5. ln afluid lift for use in wells, a pumpoperating the pumping mechanism, a casing furnishing a pressure Huid to said pressure fluid motor, a housing below said motor and having inner and outer spaced sections defining a fluid discharge passage, a packer controlling said passage, and a second packer between the casing and the outer section of the housing.

6. ln a fluid lift for use in wells, a pumping mechanism and a pressure fluid motor for operating the pumpingmechanism, a casing furnishing a pressure fluid to said pressure fluid motor, a housing having inner and outer spaced sections deining a fluid discharge passage, a packer controlling said passage, and a second packer between the casing and the outer section of the housing, said inner section of the housing being movable with respect to the outer section thereof.

7. ln a fluid lift for use in wells, a barrel,-

a fluid lifting element in said barrel and havmg mechanism and a pressure fluid motor for ing an outlet valve movable to open position on the up stroke and to closed position on the down stroke, and pressure means acting through the fluid previously elevated by said duid lifting element t0 urge the fluid lifting element downward and to seat said valve, said pressure means being located entirely within the well. I

8. In a fluid lift for use in wells, a barrel having a pumping chamber, a fluid lifting element having means to reduce the volume of said chamber on the up* stroke and being provided with an outlet valve movable to open position on the up stroke and to closed position on the down stroke, and pressure. means acting through the fluid previously elevated by said Huid lifting element to urge the fluid lifting element downward and to seat said Valve, said pressure means being located solely within the well.

9'. ln a fluid lift foriuse in wells, a barrel having an outlet portion for the reception of the fluid being elevated, a tubing receiving the fluid from said outlet portion, a reciprocating pumping element in said barrel and having an outlet valve movable to open position on the up stroke and to closed position on the down stroke, and a memberv betweenthe barrel andthe tubing and provided with a chamber in constant communication with the outlet portion of said'barrel and containing a pressure fluid acting through the fluid in the outlet portion of the barrel to urge the pumping element downward and to seat said out et valve.

10. In a fluid lift for use in wells, a barrel having an outlet portion for the reception of .the fluid being elevated, a tubing receiving the fluid from said outlet port-ion, a reciprocating pumping element in said barrel and having an outlet valve movableto open position on the up stroke and to closed position on the down stroke, a member between the barrel and the tubing and provided. with a chamber in constant communicationwiththe outlet portion of said barrel and containing an expansible pressure fluid acting through the fluid in the outlet portion of the barrel, to urge the barrel downward and to seat said outlet valve, and a check valve between the tubing and the said chamber. g

11. ln a fluid lift for use in wells, a member having separate high pressure chambers and separate low pressure chambers adapted for the successive reception of fluid, a pumping element having separate pumping devices for said pumping chambers and being provided with a movable fluid conduit having separate spaced sections between the high pressure chambers and between the low pressure chambers and having means associated therewith for protecting the chambers below vand separate low pressure chambers adapted for the successive reception of fluid, a pumping element having separate pumping devices for said pumping chambers .and being provided with a movable fluid conduit having separate spaced sections between the high pressure chambers and between the low pressure chambers and having means associated therewith for protecting the chambers below the same from the pressure above, a standing valve for one of said chambers and positioned in the line of flow of fluid between the sections of said conduit, a tubing receiving the fluid being elevated, and means inhibiting retrograde movement of the tubing fluid. 13. In a fluid lift for use in wells, a tubing for the reception of native well fluid, a pumping element having means to elevate the native well fluid on the down stroke and being provided with a valve movableto open position on the up stroke and to closed position on the down stroke to receive the pressure of native well fluid above to urge the pumping element downward, and a fluctuating pressure medium to urge the pumping element upward and being responsive to the pressure of the fluid in said tubing.

14. In a fluid lift for use in wells, a reciprocating pumping element having means to elevate fluid on the down stroke, means energized by the fluid elevated by said pumping element vto urge said pumping element downward, and a pressure medium to elevate said pumping element and being responsive to the said fluid energized means.

15. In a fluid lift for use in wells, a reciprocating pumping element having means effective on the down stroke to elevate native w-ell fluid, a pressure medium for action against through the native well fluid previously elevated by said pumping element to urge the pumping element downward, there being means protecting the native well fluid being elevated on the down stroke of the pumping element from said pressure medium, and a second pressure medium for moving said y pumpmg element upward.

16. In a fluid lift for use in wells, a barrel having a pumping chamber, a reciprocating plunger in the barrel and having a fluid conduit extending above the same, a housing surrounding thebarrel and the fluid conduit to cooperate therewith in the formation of a chamber of constant volume, a body of fluid in said chamber, and a fixed member. connected to said housing and closely embracing said fluid conduit to close the upper portion of saidsecond chamber and thereby substantially isolate the body of fluid therein.

17. In a fluid lift for use in wells, a pumping barrel, a housing surrounding the barrel inspaced relation thereto and having a chamber` of unchanging volume, a body of fluid substantially filling s aid chamber and extending about and above said barrel, a reciprocating plunger in said barrel and having a fluid conduit movable therewith and being in fluid tight contact with the barrel, and a fixed member associated with the upper portion of said housing and closely embracing the fluid conduit to close the upper portion of said chamber and thereby substantially isolate said body of fluid.

18. In a fluid lift for wells, a movable piston having a pumping chamber and an inlet valve in the lower portion of the pumping chamber, a fixed member depending into the movable piston and having a fluid passage, sealing devices between said piston and said fixed member, an outlet valve carried by said fixed member and located within said piston, said piston being movable upwardly to discharge the contents of said chamber through said outlet valve and said passage, said outlet valve being spaced inward from the sides of said piston to cooperate therewith in the formation of a gas trap between said pumping chamber and lsaid sealing device.

19. In a fluid lift for wells, a movable piston having a pumping chamber and an inlet valve in the lower portion of the pump-ing chamber, a fixed member depending into the movable piston and having a fluid passage,

sealing devices between said piston and said fixed member, and an outlet valve carried by said fixed member and located within said piston, said piston being movable upwardly todischarge the contents of said chamber through said outlet valve and said passage,

said outlet valve being spaced inward from said piston to cooperate therewith in the formation of'a gas trap between said pumping chamber and said sealing devices, and a plunger in said fixed member and movable in unison with saidpiston. .l

- 20. In a fluid lift for use in wells, a movable piston having a pumping chamber, an

inlet valve in the lower portion of the chamber, a fixed member depending into the piston and having a working contact therewith( a plunger movable with said piston and extending upwardly'into said fixed member,f l

said piston being movableupwardly to discharge the fluid from said chamber into the fixed member, said depending fixed member having the lower portion thereof spaced inwardly from the wall of said piston and cooperating therewith in forming a gas trap between said pumping chamber and the working Contact between the fixed member and said piston. 1

21. In a fluid lift for use in wells, inner and outer spaced members havin a chamber, an initially compressed body o gas within said chamber, a pumping element and a piston extending into said chamber and urged to extreme position by the gas therein, and a member having a fluid trap'above said chamber and in the line of flow of gas from said chamber, said pumping element being opposed to and being responsive to the accumulated pressure in said trap.

22. In a fluid lift for use in wells, a tubing for the reception of native well fluid, a pumping element movable downward under the influence of the descending native well tubing fluid and having means effective on the down stroke thereof for elevating the native well fluid, and means between the descending tubing fiuid and the ascending native well Huid to maintain the same separate during opposite movement.

23. In a fluid lift for use in wells, a tubing for the reception of native well Huid, a pumping element movable downward under the infiuence of descending native well tubing fluid and having means effective on the down stroke for elevating the native well fluid, a member having a pumping chamber receiving the aforesaid ascending native well fluid and maintaining the same separate from the descending tubing fluid during opposite movement of these fluids, and means effective on the up stroke of the pumping element to discharge the fluid elevated thereby into the native well fluid in the tubing.

24. In a fluid lift for use in wells, a piston having a pumping chamber associated therewith, a plunger having a lower inlet valve and an upper outlet valve, a tubing for the reception of fluid from said chamber, said piston being movable upwardly to discharge the fluid in said chamber through said outlet valve on the up stroke and to simultaneously raise the tubing fluid, said outlet valve being movable to closed position on the down stroke.

25. In a fluid lift for use in wells, a reciprocating pumping element having fluid elevating means, a member having a chamber, an initially isolated and compressed body of gas in said chamber, a piston havipg connection with said reciprocating umping element and movable into said cham er, said piston having a cross-sectional area less than that ofsaid chamber and being exposed to the pressure in the chamber, and a pressure medium for moving the piston against the pressure of the gas in said chamber.

26. In a fiuid lift for use in wells, a member having a reciprocating pumping element, a tubing for the reception of fluid elevated by said pumping element and means trapping the pressure of the tu ing fluid incident to the ascent of such fluid in the tubing and acting independently of the Huid in the tubing to urge the piston downwardly.

27. In a fluid lift for use in wells, a member having a reciprocating pumping element, a tubi-ng for the reception of fluid elevated by said pumping element, means trapping the pressure of the tubing fluid incident to the ascent of such fluid in the tubing and acting independently of the fluid in the tubing to urge the piston downwardly, and

means in the line of pressure between the tubing and said trapping means to inhibit retrograde movement of the tubin fluid.

28. In a fluid lift for use in wel s, a member having a reciprocating pumping element provided with means for lifting fluid, a tubing for the reception of fluid elevated by said pumping element, a body of gas enc-rgized through the ascent of the pumping element and the fluid elevated thereby to urge the pumping element downwardly, and a pressure fluid motor to move the pumping element upwardly, said body of gas being entirely within the well and acting against said pumping element, there being means between said body of gas and the fluid in the tubing to inhibit retrograde movement of the tubing Huid. y

29. In a fluid lift for use in wells, a member having a reciprocating pumping element provided with means for lifting fluid, a tubing for the reception of fluid elevated by said pumping element, a bodyof gas energized through the ascent of the pumping element and the fluid elevated thereby to urge the pumping element downwardly, and a pressure fluid motor to move the pumping element upwardly, and means embodying a valve in the line of pressure between the fluid in said tubing and said body of gas inhibiting retrograde movement of the fluid in the tubing, said body of gas being entirely within the well and acting against said pumping element. c

80. In a fluid lift for use in wells, a member havin a pumping element for lifting fluid, a tu ing for the reception of fluid being recovered and a plurality of separate chambers in communication with the tubing to receive a portion of the gas from the fluid being recovered, the combined forces of the gas within the separate chambers being of greater magnitude than the pressure of the Huid within the tubing and positioned to urge the pumping element downwardly.

In testimony whereof I affix my signature.

JOHN PENROD. 

